• Transactions on Electrical and Electronic Materials
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• 제6권4호
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• pp.140-143
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• 2005

Carbon Nanotube(CNTs) counter electrode is a promising alternative to Platinum counter electrode for dye sensitized solar cells (DSSCs). In this study, CNT counter electrodes having different visible light transmittance were prepared on fluorine-doped tin oxide (FTO) glass surface by spray coating method. Microstructural images show that there are CNT-tangled region coated on FTO glass counter electrodes. Using such CNT counter electrodes and screen printed $TiO_2$ electrodes, DSSCs were assembled and its I-V characteristics have been studied and compared. Light energy conversion efficiency of DSSCs increased with decreasing in light transmittance of CNT counter electrode. Efficiency of DSSCs having CNT counter electrode is compatible to that of Pt counter electrode.

• Journal of Magnetics
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• 제16권2호
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• pp.140-144
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• 2011

We report on a numerical calculation study of two new functional properties in magnetic tunnel junctions (MTJs), negative dynamic resistance and RF amplification. The magnetic dynamics in a conventional CoFeB/MgO/CoFeB MTJ with in-plane magnetization was investigated using a macro-spin model simulation. To examine the influence of thermal fluctuations, random external magnetic fields were also included. Using a voltage controlled bias circuit, the negative dynamic resistance was obtained from time averaged I-V characteristics at both 0 K and 300 K under appropriate external magnetic fields and bias voltages. Using this negative dynamic resistance property, we demonstrated RF amplification with a 100 MHz high frequency signal. Sizable RF amplification gain was observed without thermal fluctuation. However, at 300 K, the RF signal was not amplified because low frequency magnetization dynamics were dominant.

• Bulletin of the Korean Chemical Society
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• 제19권11호
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• pp.1165-1168
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• 1998

2-Tetrahydropyranyl methacrylate with a self-crosslinkable moiety was copolymerized with methyl methacrylate and 4-[(2-methacryloxyethyl)methylamino]-4'-nitrostilbene or 4-[(2-methacryloxyethyl)ethylamino]-4'nitroazobenzene to provide second-order nonlinear optical property. Glass transition temperatures (Tg of the copolymers are around 140 ℃. The copolymers were soluble in common organic solvents such as tetrahydrofuran (THF), cyclohexanone, and N,N-dimethylformamide (DMF). Poling was carried out at 140 ℃ for 20 min and identified with UV-Vis spectroscopy. Electro-optic coefficient (r33) of copolymer was 62 pm/V for polymer 2 at 633 nm, and relaxation did not remarkably occur due to the formation of a crosslinked network at 200 ℃ for 15 min.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.140.1-140.1
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• 2008

• 대한방사선기술학회지:방사선기술과학
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• 제24권1호
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• pp.49-53
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• 2001

A number of radionuclides of interest in nuclear medicine are short lived isotopes that emit only gamma ray. The most of all Dept. of Nuclear Medicine in the hospt. are using the $^{99}Mo-^{99m}Tc$ generator for elution of the short lived isotope $^{99m}TcO_4$. A $^{99}Mo-^{99m}Tc$ generator consists of an alumina column on which $^{99}Mo$ is bound. The parent isotope($^{99}Mo$ : half life 67 hr.) decays to its daughter $^{99m}TcO_4^-$ which is a different element with a shorter half-life. $^{99}Mo$ emitted 41-keV(1.3%), 141-keV(5.6%) 181-keV(6.6%) and 366-keV(1.5%) gamma rays. But $^{99m}TcO_4$ emitted only 140-keV gamma ray. We study about the gamma ray distribution around the $^{99}Mo$ generator. And obtained the result as follows ; 1. Total counted gamma ray from generator smaller in front side than back. 2. The gamma ray emitted from $^{99}Mo$ generator without $^{99m}TcO_4$ vial increased in the back side(Mo column posited side) 3. The gamma ray only from the $^{99m}TcO_4$ vial increased in the front side. 4. Apron can protect gamma ray above 60% of total radiation from the $^{99}Mo$ generator.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.342-345
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• 2002

A new lateral trench electrode IGBT with p+ diverter was Proposed to suppress latch-up of LTIGBT. The p+ diverter was placed between the anode and cathode electrode. The latch-up of LTEIGBT with a p+ diverter was effectively suppressed to sustain an anode voltage of 8.7V and a current density of 1453A/$\textrm{cm}^2$ while in the conventional LTIGBT, latch-up occurred at an anode current density of 540A/$\textrm{cm}^2$. And the forward blocking voltage of the proposed LTEIGBT with a p+ diverter was about 140V. That of the conventional LTIGBT of the same size was no more than 105V. When the gate voltage is applied 12V, the forward conduction currents of the Proposed LTEIGBT with a p+ diverter and the conventional LIGBT are 90mA and 70mA, respectively, at the same breakdown voltage of 150V.

• 한국작물학회지
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• 제61권1호
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• pp.57-63
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• 2016

콩 재배 및 이용확대를 위한 기초자료를 얻기 위해 발아과정 중 기능성 성분인 soyasaponin의 함량 변화를 조사하였다. 1. Soyasaponin I과 soyasaponin II의 함량은 품종에 따라 차이가 있었으나 발아과정 중 떡잎부위에서 함량이 10배 이상 증가하였고, soyasaponin I은 배축에서도 종자 당 이 $140{\sim}360{\mu}g$ 수준의 함량을 나타내었다. 2. Soyasaponin III 및 soyasaponin V의 함량은 발아를 통해 증가하는 경향이었고, soyasaponin V의 경우 배축에서 그 함량이 급격히 증가하는 것으로 나타났다.

• 한국전기전자재료학회논문지
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• 제15권9호
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• pp.750-757
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• 2002

A new lateral trench LTEIGBT with p+ diverter was proposed to suppress latch-up of LTIGBT The p+ diverter was placed between the anode and cathode electrode. The latch-up of LTEICBT with a p+ diverter was effectively suppressed to sustain an anode voltage of 8.7V and a current density of 1453A/$\textrm{cm}^2$ while in the conventional LTIGBT, latch-up occured at an anode current density of 540A/$\textrm{cm}^2$. In addition, the forward blocking voltage of the proposed LTEIGBT with a p+ diverter was about 140V. The forward blocking voltage of the conventional LTIGBT of the same size was no more than 105V, We fabricated the proposed LTEIGBT with a p+ diverter after the device and process simulation was finished. When the gate voltage is applied 12V, the forward conduction currents of the proposed LTEIGBT with a p+ diverter and the conventional LIGBT are 90㎃ and 70㎃, respectively, at the same breakdown voltage of 150V.

• 한국표면공학회지
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• 제49권2호
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• pp.135-140
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• 2016

In this study, we prepared magnesium ion containing oxide films formed on the Ti-6Al-4V using plasma electrolytic oxidation (PEO) treatment. Ti-6Al-4V surface was treated using PEO in Mg containing electrolytes at 270V for 5 min. The phase, composition and morphology of the Mg ion containing oxide films were evaluated with X-ray diffraction (XRD), Attenuated total reflectance Fourier transform infrared (ATR-FTIR) and filed-emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectrometer (EDS). The biocompatibility of Mg ion containing oxide films was evaluated by immersing in simulated body fluid (SBF). According to surface properties of PEO films, the optimum condition was formed when the applied was 270 V. The PEO films formed in the condition contained the properties of porosity, anatase phase, and near 1.7 Ca(Mg)/P ratio in the oxide film. Our experimental results demonstrate that Mg ion containing oxide promotes bone like apatite nucleation and growth from SBF. The phase and morphologies of bone like apatite were influenced by the Mg ion concentration.

• 생물환경조절학회지
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• 제27권2호
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• pp.140-146
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• 2018

코이어 더스트와 수피를 동일한 비율로 혼합한 상토로 '싼타' 딸기를 수경재배할 때 기비로 혼합된 유황의 처리수준 차이가 토양용액의 중탄산 농도, pH, 식물체의 생육 및 무기원소 흡수량에 미치는 영향을 구명하기 위해 본 연구를 수행하였다. 혼합상토 조제시 유황분말을 0, 0.23, 0.45, 0.90 및 $1.80g{\cdot}L^{-1}$으로 조절하여 혼합하였고, 작물 재배 중에는 중탄산 농도를 $240mg{\cdot}L^{-1}$으로 조절한 Hoagland 용액을 관비하였다. 식물체의 생육조사 및 무기원소 함량 분석은 양액처리 140일 후에, 근권부의 화학성 분석은 매 2주 간격으로 수행하였다. 유황의 시비수준이 증가할수록 모주의 전반적인 생장이 우수하였다. 엽록소 함량을 제외한 모주의 생장조사 항목에서 무처리구가 가장 저조하였고, $0.45g{\cdot}L^{-1}$ 이상의 세 처리구 간에서 통계적인 차이가 인정되지 않았다. 유황 처리수준이 높아질수록 런너 발생 및 자묘의 생장 역시 우수해지는 경향을 보였다. 런너 길이, 모주당 발생한 자묘수 및 1번 자묘의 생체중은 $0.45g{\cdot}L^{-1}$ 보다 낮은 유황처리구보다 0.90과 $1.80g{\cdot}L^{-1}$ 처리구가 우수하였지만 두 처리 간에는 통계적인 차이가 없었다. 유황 0과 $0.23g{\cdot}L^{-1}$ 처리구는 토양용액의 중탄산 농도와 pH가 지속적으로 상승한 반면 $0.90g{\cdot}L^{-1}$ 이상 처리구에서 다소 낮아지는 경향이었다. 토양용액 내 K과 $PO_4$의 농도는 0.90과 $1.80g{\cdot}L^{-1}$가 다른 처리구보다 낮았으며, Ca과 Mg의 농도는 처리구 간에 차이가 없었다. 유황 무처리구에서 분석한 무기원소 함량이 가장 적었으며, 유황 처리수준이 높아질수록 증가하였다. 이상의 결과, 코이어 더스트와 수피 혼합상토(5:5, v/v)에서 '싼타' 딸기를 수경재배할 때 양액의 중탄산 피해를 방지하고 식물 생육을 촉진시키기 위해서는 유황을 $0.90g{\cdot}L^{-1}$ 이상 기비처리하는 것이 효과적이라 판단하였다.